mortar mix for pointing slabs.

[BML]

I had my patio Slabbed a year ago and already weeds are growing in between them. I suspect that I need to re-point them and am asking for advice on the method and mortar mix.

 

[Ian H]

I'd use a wet mix at 4-1.

Did you brush the mix in dry originally?

 

[r896neo]

Are your flags laid on sand and cement or just on unbound sand. If its the later then any pointing will not last as the bedding is slightly flexible and the movement cracks the pointing.

If they were laid on mortar then point with 4:1 plastering sand- cement. The wetter you make it (up to a point) the stronger it will be but the more messy, a pointing gun allows a nice wet mix without creating havoc.

If you dont want to use a gun then a semidry mix well compacted and ironed in is the next best bet.

 

[BML]

Did you brush the mix in dry originally?
No, the person who laid them used a wet mix which I suspect was to weak.

Are your flags laid on sand and cement or just on unbound sand. If its the later then any pointing will not last as the bedding is slightly flexible and the movement cracks the pointing.
No, they were laid on a wet mix.

If they were laid on mortar then point with 4:1 plastering sand- cement. The wetter you make it (up to a point) the stronger it will be but the more messy, a pointing gun allows a nice wet mix without creating havoc.
That looks right. By the way, whats a gun?

Many thanks to you both.

 

[Ian H]

It's like a silicone gun but bigger to take mortar

 

[^woody^]

Search for Pointmaster gun. The ones with a trigger are crap

I posted about this gun years ago in the tools forum, but it seems to have gone for some reason.

Otherwise, cardboard or ply with a slot in it to push the mortar through and protect the slabs

 

[London Mike 49]

This; http://www.pavingexpert.com/pointing.htm

Mike